1. Field of the Invention
The present invention relates to a photomask of an exposure device, having a light shielding pattern, which is used in a photolithographic process for use in the fabrication of semiconductor devices.
2. Description of the Related Art
In a photolithographic process for fabricating semiconductor devices or the like, multichip photomasks are used. In a photomask, a layout such as an arrangement of elements or a circuit pattern of semiconductor devices is defined by using a light shielding pattern of metal or the like (see, for example, Japanese Unexamined Patent Application Publication Nos. 3-121456 and 5-19448).
FIG. 5 shows a schematic configuration of a multichip photomask 50 for fabricating semiconductor devices.
The photomask 50 shown in FIG. 5 has a light shielding pattern 51 of metal such as chromium (Cr) in accordance with a layout of semiconductor devices to be formed. The light shielding pattern 51 is defined on substantially an entire surface of the photomask 50.
A plurality of chip pattern regions 53, which are indicated by broken lines, are also defined on the photomask 50. Further, scribe regions 52 for separating the chip pattern regions 53 from one another are defined between the chip pattern regions 53.
The light shielding pattern 51 is defined over the chip pattern regions 53 in accordance with a layout such as an arrangement of elements or a circuit pattern of semiconductor devices to be formed using the photomask 50.
FIG. 6 shows an enlarged view of one of the chip pattern regions 53 in the photomask 50. In the chip pattern region 53, for example, in order to form an independent island-shaped layout on a semiconductor device or the like, an island-shaped isolated light shielding pattern 55 is defined so as to be surrounded by a light transmitting pattern 57 in accordance with the layout of the semiconductor device or the like.